For The Record...

[frustratedpilot]

My favorite Leslie Nielsen memory was his episode of the TV series Night Gallery, called "The Phantom of What Opera?"--which was basically a mash-up of The Phantom of the Opera and The Twilight Zone's "Eye of the Beholder"--both of which are turned upside down for laughs.

I don't know if he did comedy before then, but I think it was a turning point in his career.